Linear positioning indicators find numerous uses in manufacturing processes and materials handling systems. While such indicators can be visual readout only, numerous uses are made of indicators that can provide a remote signal for display and/or control purposes. Linear positioning indicators are especially useful in conjunction with hydraulic and pneumatic cylinders, providing a means of generating a signal that represents the positioning of a cylinder piston along the stroke of the cylinder.
Linear positioning indicators are also useful in liquid level gauges, such as described in the related applications referred to above, the specifications of which are incorporated here by reference as if a part of the present specification. In particular, the conductive/resistive element described in those specifications has been found to have use in more general applications as described therein and here. Examples of linear positioning indicators follow the article by A. L. Hitchcox in Hydraulics and Pneumatics, May, 1995, p. 38.